US1838025A - Method of making chain links - Google Patents

Description

Dec 22, 1931. R E WALDRON 1,838,025

METHOD OF MAKING CHAIN LINKS Filed Dec. 22, 1924 2 Sheets-Sheet l z A danvemtoz D86. 22, 1931. WALDRON 1,838,025

METHOD OF MAKING CHAIN LINKS Filed 1924 2 Sheets-Sheet 2 71 vsnscll 15f Wi r z Patented Dec. 22, 1931 V PATENT OFFICE RUSSELL E. wALDnon, ornnrnorr,

MICHIGAN, ASSIGNOR T DOMINION ronen &

STAMPING COMPANY, LIMITED, OF- WALKERVILLE, ONTARIO, CANADA, A CORPO- BATION OF ONTARIO, CANADA 1 METHOD or MAKING CHAIN LINKS )7 Application filed December 22,'1924.: Serial No. 757,505.

'Ihis'invention relates to chain links and particularly to a method of producing the same, 7

The invention contemplates the production of chain links provided with parallel surfaces by a die forging method wherebylinks for instance of relatively-large dimensions designed for use in conveyor chams and the like may be cheaply and quickly man: ufactured.

The various objects and this invention will be made more apparent as the description proceeds especiallywhen considered in connection withthe accompanying drawings wherein: e v

Figure 1 is a fragmentary PBISPBCUVB'VIBW of a chain'showing a link constructed in accordancewith the invention; 1

Figure 2 is a separated perspective View of the original forg ng dies; I

Figure '3 is a sectional view throughthe original forging dies withthework'piece 1n position; i

Figure & is a perspective of the work piece after it leaves the original forging dies; Figure 5 is a sectional view through the Y punching die employed forxtrimming tl1e flash or excess material from the work plece';

Figure -6 is a similar view showing the die parts and work piece after the trimming operation; 1 1

Figure 7 is a-sectiona'l view through the punching die employed for removing the web from the center of the link;

Figure 8 is an enlarged sectional view showing the transverse shape of the link after it leaves the punching press shown in Figure 7' i Figure 9 is a separated perspective view of the clamping'die and stretchingpunch employed for surfacing the ends of the link to produce parallel surfaces and Figure 10 is a sectional view showing'th'e parts illustrated in Figure 9 after-the operation upon the link. Y Y Referring now particularly to the drawings' wherein like characters indicate like parts, it will be noted that thereis illustrated in Figure 1 a section of a conveyor chain comprising link members 10 which are aladvantages of ternately arranged with link members formed by a pair of members 11, pivotal connection between the members 10 and 11 being provided by pivot pins 12 disengageably connected to the members 11. In practice the surface 13- at each end of the link member 10 has a bearing engagement with the pin 12 of each link while the exterior end surfaces 14: of each link member 10 are engageable by the teeth of the sprocket wheel (not shown). r

He'retofore the practice has been in general to forge or cast the link members 10 with substantially centrally arranged longitudi nally extending inner and outer draft or bevelportions 15 and 16 respectively. In order toremove these raised portions and produce a suitable bearing surface on the inner ends 13 of the links the latter were usually machined at this point, while in many instances no cons deration was given to the outer end surface 14 that engaged the teeth of the sprocket wheel. The result of this practice was that the cost of production of the links 10 was materially increased as well as the time required for manufacture. Furthermore, the constant engagement of the bevels or drafts 16 with the teeth of the sprocket Wheel proved costly in that this action occasioned unusual wear to I the teeth. 7

An important object of this invention is therefore to produce chain links substantially similar to the links 10 bya die forging method. Another object is to provide means, during the production of the links for redistributing the metal wat the ends of the link and for so shaping these ends as to produce parallel interior and exterior surfaces affording satisfactory bearing surfaces for the pins 12 and for the teeth of the sprocket wheel. 7 w

In practicing this invention a forging 'die similar to that illustrated in Figures 2 and dis preferably employed comprising upper and lower die members 17 and 18 between whicli'the blank is inserted to form a work piece 19-such as shown in Figure 4. .In actual practice the'blank is in the form of a bar, the end of" which is inserted betweenthe die members 17 and 18 and after the formation of the work piece 19 it is sheared off from the remainder of the blank, on the next operation of the die members, by means of the shearing members 20 carried respectively by the die members 17 and 18. v

The work piece as it comes from the original forging dies comprises in addition to the main link body a circumferential flange 21 of excess material or fiashing as well as a central web or slug 22.

In Figures 5 and 6 there is illustrated a punching die comprising upper and lower die members 23 and 24 by means of which the flashing 21 is sheared off or removed from the outside of the work piece. {is will be noted from an examination of Figures 5 and 6, the work piece 19 is placed upon the die member 24: andis, punched through this die member by the upper dieinember "23 and the flashing vorexcess material 21 is trimmed while the central web thereof therefrom.

In Figure Tthereis illustrated a punching die comprising upper and lowercdie members 25 and 26 by means of which the web or slug in the center of the work piece is renewed. In carrying out this-operation the work piece 19 is supported upon the lower'die member is engaged by the upper die memberand removed from the work piece by a punching operation, I

The exterior conformation of the work iece or link at this stage is illustrated in igure 8. The draft or bevel on the outer and inner sides of the link is shown,--somewhat exaggerated, for the purpose ofv emphasizingthe importance of the next. step of this method by which these vertical sides of the link, particularly at the ends thereof, .are flattened or straightened, by a redistribution of the metal, to form inner and outer bearing surfaces for the purpose hereinbefore mentioned. V I

InFigures 9 andlO the meansfor carrying out the last step of this method is illustrated. For this purpose there is. preferably provided a clamping die composed of die members 27 and 28 into which the work piece or link the manner clearly shown. The work piece or link rests in a recess formed by theslots 29 of the two die clamping members, the ends 30 of this recess being squared with reference to the longitudinal axis of the recess whereby the ends of the link 19 when forced into e11 gagement therewith will consequently be squared or flattened with reference to the longitudinal axis of the link To aflord means for handling thework piece 19 and for protecting the same against the clamping action ofthe die clamping members 27 and 28 there is provideda combined handling tool and filler block 31 which may rest within a longitudinal depression 32 formed in the die members and longitudir of the link. As the stretching 19 is adapted to be placed, in

nally displaceable therein. At the beginning of this last stage of the method this filler block 31 extends within and preferably through the work piece or link 19 as shown in Figure 9. The sides of the link are there fore'prevented from collapsing so that no difliculty will be experienced in forcing the stretching punch 33 into and through the hole punch 33 approaches the work piece it first engages the filler block 31 and moves the same longitudinally from engagement with the work piece as will be obvious;

The stretching punch 33 is preferably provided with a tapering forward end 34 to facilitate the entrance of the punch into the hole of the link, the, longitudinal edges 35 of this punch being parallel. The vertical dimension of this punch, as seen in Figure 9, is such-as to-causea stretching or expansion of the work piece 19 within the recess 29 of the clamping die. r v V Itwill beunderstood that the stretching punch acts principally upon the ends of the work piece, the engagement of this punch withthe inner end surfaces 13 causing a flattening or redistribution of themetal and a forcing'of the excess material outwardlywith the result that the outer end surfaces 14 are pressed up against the squared ends 30 of the work piece recess. Consequently the inner and. outersurfaces of the link, at the ends thereof, are rendered substantially parallel to .one another to form suitable bearing surfaces. 1 V 7 By practicing-the herein described method chain links and the like may be for-med by die forging and provided with suitable bearing surfaces without necessitating a machining operation whereby the cost and time of production is reduced to a minimum. While the method hasbeen described as including several'distinct steps it will be immediately obvious to those skilled in the art, thatlone or bined by properly constructing the die members andto this end the invention contemplates such'modifications in the manner of executing the same asmaycome within the purview of the accompanying claims.

What I claim as my invention is:

1. The method of links having their ends provided with parallel interior and exterior surfaces which consists of die forging the link from a blank, removing the excess material by die punching and removing the draft ,or bevel from the ends of the link by clamping the link in a clampingdie with the die embracing the ends of the link and forcing a stretching punch intotheihole of the link. I

2. The method of producing forged chain links having their ends provided with paralmore of the several operations may be com- .lel interior-and exterior surfaces which conproducing forged, chain removing the excess material from the exterior and interior of the link and removing the bevel from the link at predetermined points by clamping the link in a clamping die with the die embracing the ends of the link and. forcing a punch into the hole of the link.

3. The method of producing forged chain links provided with parallel surfaces which consists of die forging the link from a blank, removing the excess material from the exterior and interior of the link and removing the draft or bevel from the ends of the link by clamping the link, mounted on a filler block, in a clamping die and subjecting the link to the action of a stretching punch which displaces the filler block and enters the hole of the link. 7

In testimony whereof I aflix my signature.

RUSSELL E. WALDRON.

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